The physics of the process is better represented using the kinetics of gas hydrate formation at three stages. The initial stage is the transport of gas through the gas-water interface into the liquid phase. The second stage is the induction period which includes the absorption of gas by the liquid water, and the cavity restructuring and closure. The third stage is the sustained growth of nuclei as solid hydrate particles. The effect of mixing and migration of the formed hydrate crystalline particle inside the closed tank is also taken into account. The parameters of the model are determined by analyzing typical experimental data using this model.
The results developed can be used for determination of the gas diffusivity, rate of hydrate formation, pressure decline in the tank, hydrate volume fraction, and the thickness of hydrate crystals accumulating at the gas-liquid interface. The model can be utilized to determine the values of the various model parameters, including the various rate coefficients and the diffusion coefficient of the gas in a three-phase system by regression of the resultant expressions to experimental data. It is concluded that the model developed in this study can help analyze the laboratory PVT tests accurately.